Power unit and governor for household food mixer



w. F. BISLEY 2,612,571

POWER UNIT AND GOVERNOR FOR HOUSEHOLD FOOD MIXER Sgpt. 30, 1952 3 Sheets-Sheet 1 Original Filed June 20. 1947 WH/PPIN III II I s Sept. 30, 1952 w, B|sLEY 2,612,571

POWER UNIT AND GOVERNOR FOR HOUSEHOLD FOOD MIXER Original Filed June 20, 1947 3 Sheets-Sheet 2 )6 la; /6/ I82 I 452 /04 mg Sept. 30, 1952 Q w. F. BISLEY 2,612,571

POWER UNIT AND GOVERNOR FOR HOUSEHOLD FOOD MIXER Original Filed'June 20. 1947 3 Sheets-Sheet 3 Q 7? me Ina/692%?- ZW f? Btifky.

Patented Sept. 30, 1952 POWER UNIT AND GOVERNOR FOR HOUSEHOLD FOOD MIXER William F. Bisley, Oak Park, Ill.

(Friginal application June 20, 1947, Serial No. 755,995. Divided and this application May 12,

1948, Serial N0. 26,650

7 Claims.

The present invention relates to food mixers and more particularly to food mixers having interdigitating heaters depending from a power unit overhanging a bowl.

This application is a divison of application Serial No. 755,995, filed June 20, 1942.

The invention is further characterized by a manually operable speed control ring located where it can be managed and thepower unit tilted by one hand with the above mentioned lateral push, whereby the motor speed can be reduced as the beaters come out of the mixture one at a time while the other hand remains free to manage the bowl or scraping utensils.

A further object of the invention is to provide a speed control for the food mixer which can be observed and managed from both sides of the power unit.

Another object of the invention is to provide an improved control for a rotary centrifugal responsive make-and-break speed governor which divides in a balanced way at widely spaced points the frictional load of its cam adjustment for ease of operation and assembly with no danger of creep from a set position existing during operating periods of the power unit.

The invention is further characterized by an arrangement of a cooling fan upon the rotary centrifugal speed governor which is shrouded by a manually actuated ring assembly which also controls the governor.

Other objects and advantages including ruggedness and ease of assembly and servicing will be apparent from the following description, the claims attached thereto, and the accompanying drawings, in which similar reference characters identify similar parts throughout the several views.

Referring to the drawings:

Fig. 1 is a side elevational view or an electric food mixer of the household type, partly in section, embodying the invention;

Fig. 2 is an enlarged vertical section taken on a plane passing through the axis of the motor drive showing the construction and arrangement of the elements of the power unit;

Fig. 3 is a top plan view partly in medial section of the power unit shown in Fig. 2; and

Fig, 4 is a vertical section taken upon line 4-4 of Fig. 2.

Referring to Fig. 1, the electric food mixer embodying the invention preferably includes a power unit 2%, a base 2!, a standard or support construction 22, turntable and bowl construction 23, an agitator 24, and a juicer attachment (not shown).

Power unit Referring now to Figs. 2 and 3, the framework of the power unit 26 comprises a rough inner casing having front and rear sections Hi2 and [03, respectively, held together by stud bolts [64 and elongated units I05. The front section IE2 is bored and reamed concentrically to receive a front armature bearing and a stator lOl of a series wound fractional horsepower electric motor I08.

The rear section I03 carries a rear inboard motor bearing I50. An outer surface lid of the section I03 is turned down to receive rigidly a decorative plastic band I52 flush with the outer marginal edge of the shell lZi) to cover upopen ings through the side of the rear section ltd, which openings are provided for inspection and access when the band is removed.

The bearing I50 is secured within a cylindrical aperture formed in a supporting member I53 which extends radially inward from the inner surface of the rear casing 33. A dielectric plate l55 mounted on a shoulder formed in the member I53 supports electrical components (not shown) of a motor control circuit which is similar to that shown in Behar Patent 2,262,912. Briefly, the rotating part includes a plastic cast ing having two axially spaced collector rings llil on its hub, fan blades 32 on its periphery, and centrifugal and adjustable make-and-break contacts [63 on its end face with a lever I lit to determine the speed at which the contacts separate. As shown in the drawings the normally closed contacts of the switch which include contact supporting springs are located to flux outwardly together under the action of centrifugal force when the governor It!) is rotating. However, the out ward movement of the inner contact is limited by the lever I64 and its associated linkage so that the outer contact will break contact with the inner one when the centrifugal force is great enough to flex the outer contact farther than the inner contact is permitted to go. The limit thus established for the inner contact is varied at will by varying the adjustment of the lever so that the critical point and thereby the critical speed of the armature at which the centrifugal force operates to separate the contacts of the switch can be varied to maintain the motor at any predetermined speed. An insulating button [69 is carried by the lever {64 for rotation at the axis of armature rotation where it can be actuated with minimum friction by a round headed screw I55 carried on a yoke I66. Axial movement of the screw I55 toward the left as viewed in Fig. 2 rotates the lever I34 in a counterclockwise direction to carry a link 200 (Fig. 4) pivotally secured thereto downwardly to reduce the outward movement of the inner contact I63 whereby the contacts I63 separate at a lower speed than before the adjustment. Clockwise rotation of the lever I64 moves the link 266 vertically upward so that the contacts I63 separate at a higher speed than before the clockwise rotation of the lever I64.

Brushes I61 which contact the collector rings I6I are carried by the insulating plate I68 held in place by bolts I04 secured to the units I05.

Radially around the fan I62 the section I63 has a continuous circular flange "I which closely approaches the periphery of the blades to provide a shroud or baffle for the fan. On theouter surface of this flange, an adjustment ring I12 is journalled as at I13 for rotation between limits of approximately 90. On its rear surface the ring I12 is provided with two identical cam surfaces I14 (Fig. 4) molded integrally therewith and the ends I15 (Fig. 3) of the yoke I66 slide on these cam surfaces as the ring I12 is rotated. The ends I15 of the yoke I66 are held against turning by guideways I16 (Figs. 3 and 4) cast in the rear of the ring I12.

A finishing cap I19 rigidly secured to the rear end of the flange I" by screws I11 carries the rear end of a handle I24 by screw I18 and a central hub member I60 bored as at IBI receives in sliding and centering relationship a head I82 on the yoke I 66 so that the two ends I15 and the sliding head I82 provide a three-point suspension for the yoke I66 to move forwardly and rearwardly as the ring I12 is rotated, the yoke I66 being urged to contact the cam surfaces I14 by a compression spring I83 encircling the hub I86 and contactin the yoke I66.

Movement of the yoke I66 is transmitted to the governor lever I64 by a round-headed screw I65 engaging the insulating button I69 and threaded through the yoke head I82 where it receives a lock nut I84. The head I82 is kerfed as at I85 to provide a zeroing adjustment of the governor assembly once a slug is set at the front end of the armature shaft.

Electrical leads I86 are brought into the power unit through an opening I81 at the rear of the cap I19 and are carried forwardly to the electrical components through an opening I88 in the" Air for cooling the motor is drawn through openings I90 in the rigid cap I19, as moved by the fan I62, and is exhausted upwardly through openings I2I under the handle I24.

With this arrangement the speed of the motor is infinitely varied by long cams of gradual inclines which divide the frictional load and the take-up spring tension load imposed on the system between them so that the ring i operable by hand smoothly and easily with no danger of it slipping from a set position while the motor is running. Moreover, the ring can be operated from either side of the mixer and also while the power unit is being tilted.

What is claimed is:

l. A speed control for a food mixer comprising a body adapted to be mounted on the end of a shaft for rotation therewith about a predetermined axis and carrying a centrifugally influenced switch and a control for the switch having a movable member located at the axis of rotation, a yoke having a central element engaging said movable member at the axis of rotation, a rotary speed adjustment element having cams thereon engaged at the ends by the arms of the yoke to move the yoke in an axial direction and adjust the movable member when the speed adjustment element is rotated, means for supporting said central element at said axis of rotation, and means for supporting the arms of the yoke against rotation.

2. The combination called for in claim 1 in which said member mounted upon the shaft is provided with fan blades extending outwardly from the periphery thereof, and the last said means supporting the yoke arms against rotation has a body portion closely surrounding said blades to provide a shroud.

3. In a food mixer having a housing and shaft journalled therein whose speed is to be controlled, a speed control comprising a body adapted to be mounted on the end of the shaft for rotation therewith and carrying a centrifugally influenced switch and a control therefor having a movable member located at the axis of rotation of the shaft, a yoke having a central portion engaging said movable member to displace it in an axial direction and having radially disposed arms extending from said central portion, a manually movable member mounted on the housing having cams thereon engaged by the arms of the yoke to shift the yoke in an axial direction when the movable member is moved, means upon said housing for supporting the arms of the yoke against rotation, and means upon the housing supporting the central portion of the yoke at said axis of rotation.

4. The combination called for in claim 3 in which the last said means comprising a boss upon which said central portion slides, said boss having an opening therethrough to the outside of the housing for access to said central portion, and in which said central portion carries an adjustment screw-whose inner end engages said switch control.

5. In a food mixer having a housing and a shaft journalled therein whose speed is to be controlled, a speed control comprising a body adapted to be mounted on the end of the shaft for rotation therewith and carrying a centrifugally influenced switch and a control therefor having a movable member located at the axis of rotation of the shaft, resilient means urging said element in one direction axially, a yok mounted on the housing having a central portion engaging said element to displace it in opposite axial direction, said yoke having diverging arms extending radially from said central portion, manually movable cam means mounted on the housing to engage said yoke arms, means for supporting the central portion of the yoke for movement axially of said axis of rotation, and resilient means for urging said yoke arms into contact with said cam means towards said movable member.

6. In a food mixer having a housing and a shaft journalled therein whose speed is to be controlled, a speed control comprising a body adapted to be mounted on the end of the shaft for rotation therewith and carrying a centrifugally influenced switch and a control therefor having a movable member operable upon the side of th body remote from the main portion of the shaft, resilient means urging said element in one direction axially, a yoke element having a central portion engaging said movable member to displace it in an opposite axial direction, said yoke having diverging arms extending radially from said central portion, a cam element engaged by said yoke arms, one of said elements being mounted on the housing for rotatable movement and the other element being mounted on the housing and supported against rotatable movement, and resilient means for urging said yoke arms into contact with said cam element in a direction towards said movable member.

7. In a food mixer having a housing Journalling a shaft, a speed control comprising a body mounted on the end of the shaft for rotation therewith and carrying a centriiugally influenced switch and a control therefor having a movable member located at the axis of rotation of the shaft, a boss on said housing having an opening therethrough coaxial with said shaft, a second member having a central portion slidably mounted in said opening, an element carried by said central portion engaging said movable member and accessible for adjustment with respect to said central portion throughsaid opening, cam

means carried by said housing and engaging said second member, and resilient means urging said central portion to maintaincontact between said movable member and said element.

, Y WILLIAM F. BISLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

